Method for determining azo dye and isocyanate harmful substances in textile

Abstract

The invention provides a method for determining azo dye and isocyanate harmful substances in textiles. The method comprises the following steps: preparing a standard working solution of the azo dye and isocyanate harmful substances; preparing artificial sweat and a textile sample; transferring a certain amount of the infiltration test solution, adding methanol, carrying out water bath impurity removal to obtain an azo test solution, carrying out reduction extraction on the azo test solution to obtain an aromatic amine extract, and drying to obtain an aromatic amine derivative mixture; transferring a certain amount of the infiltration test solution, adding di-n-butylamine, extracting and deriving to obtain a urea derivative solution, and drying to obtain a urea derivative mixture; the aromatic amine derivative mixture and urea derivatives are subjected to volume metering through methanol, and a to-be-detected solution is obtained; and carrying out instrumental analysis on the standard working solution and the to-be-detected solution of the azo dye and the isocyanate harmful substances. In the process of obtaining the aromatic amine derivative mixture and the urea derivative mixed solution, other impurities are purified, interference on detection results is reduced, and multiple azo dyes and multiple isocyanates are detected at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of textile testing, and in particular to a method for determining harmful substances such as azo dyes and isocyanates in textiles. Background Art

[0002] Isocyanates are an important chemical raw material. As chemical additives, they are widely used in chemical products such as paints, adhesives, herbicides, packaging coatings, synthetic rubber, and textiles. Isocyanates are irritating and toxic. They can irritate the skin, eyes, and respiratory tract through contact or ingestion. In severe cases, they can cause sensitization and even damage the immune system. When isocyanates migrate in textiles, they come into contact with the skin, thus affecting human health. Azo dyes are a class of chemical substances with azo groups synthesized by diazotization reaction of aromatic amines and sodium nitrite. Azo dyes have the advantages of a wide chromatographic range, a full range of colors, good color shade, and strong color fastness, and are widely used in textile industry dyeing. However, some azo dyes can be absorbed by the human body and undergo reduction reactions during long-term contact with the skin. The azo bonds are quickly broken and carcinogenic aromatic amines are released, which seriously endangers human health.

[0003] With the diversification of textile materials, the amount of azo dyes and isocyanates in textiles is increasing, which has aroused widespread concern about the safety of textiles. The presence of these chemicals poses a potential threat to health and also poses a challenge to the sustainable development and environmental protection of textiles.

[0004] However, the current determination methods of harmful substances such as azo dyes and isocyanates in textiles have many shortcomings. On the one hand, the current determination methods can usually only detect a single or a few harmful substances, which cannot meet the needs of simultaneous detection of multiple harmful substances in modern textiles. On the other hand, since textiles contain azo dyes and isocyanates, during the detection process, the aromatic amines produced by the reduction of azo dyes are easy to react with isocyanates, which interferes with the textile detection process and leads to inaccurate test results.

[0005] For example, the comparative document CN202010648214.5 discloses a trifluoroacetylated gas chromatography-mass spectrometry method for detecting banned azo dyes in textiles. Citric acid buffer solution is added and then sodium dithionite solution is added for reduction and decomposition. 0.5 mL of NaOH solution, 7 g of NaCl, and 5 mL of tert-butyl methyl ether internal standard working solution are added to the reactor, and the two phases are allowed to stand for separation; 1 mL of the upper clear liquid is obtained from the reactor, 25 μL of trifluoroacetic anhydride solution and 3 mL of NaOH solution are added, and the liquid to be tested is extracted and analyzed by gas chromatography-mass spectrometry for azo detection. This method can effectively separate carcinogenic aromatic amines and their isomers within a short detection time, avoid various false positive results, and improve detection efficiency. However, when the textile contains isocyanate, the textile cannot eliminate the interference of isocyanate on the test results during the detection process, nor can the isocyanate be detected.

[0006] Another example is the rapid detection method of banned azo dyes in dyed textiles in the comparative document CN201110350255.7, extraction reagent A: methyl tert-butyl ether, 10mL; extraction reagent B: 0.1mol / L-1.0mol / L hydrochloric acid solution, 5mL; reagent 1: 50g / LNaNO2 solution, 0.05mL; reagent 2: 25g / LNH4SO3NH2 solution, 0.5mL; reagent 3: 2% o-methoxyphenol ethanol aqueous solution by volume percentage concentration, 1mL; reagent 4: 0.5mol / LNaOH solution, 1mL; reduction reagent 1: 0.06mol / L, pH=6.0 citrate buffer, 16mL; reduction reagent 2: 200mg / mL sodium dithionite solution, 3.0mL. The liquid-liquid extraction textile reduction solution and decolorization method are used for pretreatment, and the aromatic amines are determined by color development. The pretreatment is simple and fast, which greatly simplifies the original steps. However, this solution cannot accurately test the content of banned azo dyes and cannot test the content of isocyanates. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for determining harmful substances of azo dyes and isocyanates in textiles that can accurately detect and simultaneously detect multiple azo dyes and isocyanates.

[0008] The purpose of this disclosure is achieved through the following technical solutions:

[0009] A method for determining harmful substances such as azo dyes and isocyanates in textiles comprises the following steps:

[0010] Prepare standard working solutions of azo dyes and isocyanate hazardous substances;

[0011] preparing artificial sweat and a textile sample, adding the artificial sweat to the textile sample and then heating and infiltrating the textile sample to obtain an infiltration test solution;

[0012] Pipetting a certain amount of the infiltration test solution, adding a primary alcohol solvent to the infiltration test solution for water bath removal to obtain an azo test solution, adding sodium dithionite to the azo test solution for reduction extraction to obtain an aromatic amine extract solution, and drying the aromatic amine extract solution to obtain an aromatic amine derivative mixture;

[0013] Pipetting a certain amount of the infiltration test solution, adding di-n-butylamine to the infiltration test solution for extraction and derivatization to obtain a urea derivative solution, and drying the urea derivative solution to obtain a urea derivative mixture;

[0014] The aromatic amine derivative mixture and the urea derivative mixture are diluted to volume with methanol to obtain a test solution;

[0015] Instrumental analysis is performed on the standard working solutions of the azo dyes and isocyanate harmful substances and the solution to be tested.

[0016] In one embodiment, sodium dithionite is added to the azo test solution for reduction extraction, comprising the following steps:

[0017] Adding a sodium dithionite aqueous solution to the azo test solution for water bath reduction to obtain a reduced solution;

[0018] Putting the reducing solution into ice water to cool the reducing solution to 20° C.-25° C. to obtain a cooling solution;

[0019] The cooled solution is transferred into an extraction diatomaceous earth column, and tert-butyl methyl ether is added for extraction and elution to obtain an aromatic amine extract.

[0020] In one embodiment, the temperature for heating and infiltrating after adding the artificial sweat to the textile sample is 70±2°C, and the infiltration time is 30±1min. The temperature for water bath removal of impurities by adding primary alcohol solvent to the infiltration test solution is 70±2°C, and the water bath removal time is 30±1min. The temperature for water bath reduction is 70±2°C, and the water bath reduction time is 30±1min.

[0021] In one embodiment, after obtaining the cooling solution and before pouring the cooling solution into the extraction diatomaceous earth column, the following steps are also included:

[0022] A sodium hydroxide solution is added to the cooled solution to carry out mixing and shaking treatment.

[0023] In one embodiment, drying the aromatic amine extract comprises the following steps:

[0024] The aromatic amine extract is transferred to a low vacuum rotary evaporator for concentration at a heating temperature of 35° C. to 45° C. to obtain a concentrated extract;

[0025] The concentrated extract is blown dry by an inert gas to obtain an aromatic amine derivative mixture.

[0026] In one embodiment, di-n-butylamine is added to the infiltration test solution for extraction and derivatization, comprising the following steps:

[0027] adding dichloromethane to the infiltration test solution and mixing to obtain an extraction mixture;

[0028] The extraction mixture is centrifuged at a centrifugal speed of more than 4000 r / min for 5-10 min, and after standing and stratification, an upper layer of extraction liquid and a lower layer of liquid are formed;

[0029] removing the upper layer of the extract;

[0030] A di-n-butylamine-dichloromethane solution is added to the upper extract, and after ultrasonic extraction and derivatization, a urea derivative solution is obtained.

[0031] In one embodiment, before centrifuging the extraction mixture, after adding dichloromethane to the infiltration test solution, the following steps are also included:

[0032] The extraction mixture was vortexed at a speed of 2000 r / min for 10-15 min.

[0033] In one embodiment, the process of making the aromatic amine derivative mixture and the urea derivative constant with methanol comprises the following steps:

[0034] Transferring the aromatic amine derivative mixture to a container with methanol to obtain a primary fixed volume solution;

[0035] The urea derivative mixture is washed with methanol into a primary volumetric solution in the same container, and the volume is secondarily made up with methanol to obtain a solution to be tested.

[0036] In one embodiment, preparing a standard working solution of azo dye substances and isocyanate substances comprises the following steps:

[0037] Dissolve the harmful substances of azo dyes and isocyanates in methanol to obtain primary standard stock solutions of harmful substances of azo dyes and isocyanates;

[0038] The primary standard stock solutions of harmful substances such as azo dyes and isocyanates are respectively prepared with methanol to obtain standard working solutions of azo dyes and isocyanates of different concentrations.

[0039] In one embodiment, the harmful substances of isocyanate include 4,4-methylenebis(phenyl isocyanate), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), tetramethyl-m-hydroxyethyl diisocyanate (TMXDI), cyclohexyl isocyanate, isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI), polymeric diphenylmethane diisocyanate (pMDI), toluene diisocyanate, 2,6-diisocyanate toluene, m-xylene diisocyanate, 2,6-diisopropylphenyl-isocyanate, isopropylphenyl isocyanate, 3-carboxyphenyl isocyanate, methyl isocyanate, and n-heptyl isocyanate; the azo dye substances include aniline, o-toluidine, 2.6- At least one of dimethylaniline, 2.4-dimethylaniline, o-anisidine, naphthalene-d8, p-chloroaniline, p-phenylenediamine, 3-amino-p-toluene, 2.4.5-trimethylaniline, 4-chloro-2-methylaniline, 2.4-diaminotoluene, 2.4-diaminoanisole, 2.4.5-trichloroaniline, 2-naphthylamine, 2-amino-4-nitrotoluene, anthracene-D10, 4-aminoazobenzene, 4.4-diaminodiphenyl ether, benzidine, 4.4-diaminodiphenylmethane, o-aminoazotoluene, 4.4-diamino-3.3-dimethylbiphenylmethane, o-toluidine, 4.4-diaminodiphenyl sulfide, 3.3-dichlorobenzidine, 4.4-diamino-3.3-dichlorodiphenylmethane, dianisidine, and o-toluidine.

[0040] Compared with the prior art, the present invention has at least the following advantages:

[0041] The above-mentioned method for determining harmful substances of azo dyes and isocyanates in textiles comprises the following steps: removing impurities from the impregnated test solution and then performing reduction extraction to obtain an aromatic amine derivative mixture; extracting the impregnated test solution and then performing derivatization to obtain a urea derivative mixture; re-converting the aromatic amine derivative mixture and the urea derivative mixture to obtain a test solution; when the test solution is subjected to instrumental analysis, the contents of azo dyes and isocyanates reacted with the aromatic amine derivative and urea derivative mixture of the test solution are determined; in the process of obtaining the aromatic amine derivative mixture and the urea derivative mixture, other impurities are purified, and interference with the test results is reduced, thereby improving the accuracy of azo dyes and isocyanates measured by the test solution; and a variety of azo dyes and a variety of isocyanates are detected at the same time, thereby improving the detection efficiency and reducing the detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 The flowchart of the method for determining harmful substances such as azo dyes and isocyanates in textiles;

[0044] Figure 2 A chromatogram of an azo dye of a test sample of an embodiment;

[0045] Figure 3 and Figure 4 A calibration curve diagram of quantitative analysis corresponding to a plurality of azo dyes in a test sample of an embodiment;

[0046] Figure 5 A chromatogram corresponding to multiple isocyanates of a test sample in an embodiment;

[0047] Figure 6 and Figure 7 The chromatograms corresponding to multiple isocyanates in a test sample of an embodiment and the calibration curve diagram of quantitative analysis are shown. DETAILED DESCRIPTION

[0048] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0049] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0051] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0052] The present invention relates to a method for preparing a lithium ion diaphragm. In one embodiment, the method comprises the following steps: preparing a standard working solution of azo dyes and isocyanate harmful substances; preparing artificial sweat and textile samples, adding the artificial sweat to the textile samples and then heating and infiltrating to obtain an infiltration test solution; taking a certain amount of the infiltration test solution, adding a primary alcohol solvent to the infiltration test solution for water bath impurity removal to obtain an azo test solution, adding sodium dithionite to the azo test solution for reduction extraction to obtain an aromatic amine extract, drying the aromatic amine extract to obtain an aromatic amine derivative mixture; taking a certain amount of the infiltration test solution, adding di-n-butylamine to the infiltration test solution for extraction and derivatization to obtain a urea derivative solution, drying the urea derivative solution to obtain a urea derivative mixture; constant volume of the aromatic amine derivative mixture and the urea derivative mixture with methanol to obtain a test solution; instrumental analysis of the standard working solution of azo dyes and isocyanate harmful substances and the test solution.

[0053] See also Figure 1 , which is a method for determining harmful substances such as azo dyes and isocyanates in textiles according to one embodiment of the present invention, comprising the following steps:

[0054] S101 prepares standard working solutions of azo dyes and isocyanate harmful substances. In this embodiment, the standard working solutions of azo dyes and isocyanates are used to compare the spiked recovery of the test solution measured by the determination method, so as to determine the accuracy of the test results. By configuring a plurality of standard working solutions of azo dyes and a plurality of standard working solutions of isocyanates, a plurality of substances can be tested simultaneously.

[0055] S103 prepares artificial sweat and textile samples, adds the artificial sweat to the textile samples and then heats and infiltrates them to obtain an infiltration test solution. In this embodiment, if the textile sample is an unfinished product such as yarn, fabric, etc., the textile sample is directly cut, and if the textile sample is a product composed of multiple components such as clothing, dresses, jewelry bags, etc., the sample is cut from each component, and the component may include fabric, lining, pocket cloth, embroidery, labels, artificial fur, sewing thread, etc. Take a certain amount of representative textiles and cut them into small pieces of about 5mm*5mm, weigh 1.0-3.0g, accurate to 0.01g. Artificial sweat can simulate the migration amount of harmful substances leaching and contacting with the human body after human sweating, skin, sweat and textiles contact. By heating and infiltrating the textile sample, the textile sample is fully contacted with artificial sweat, so that azo dyes and isocyanate harmful substances migrate into the infiltration test solution.

[0056] S105: pipette a quantitative amount of the infiltration test solution, add a primary alcohol solvent to the infiltration test solution for water bath impurity removal to obtain an azo test solution, perform reduction extraction on the azo test solution to obtain an aromatic amine extract, and dry the aromatic amine extract to obtain an aromatic amine derivative mixture. In this embodiment, the amount of the infiltration test solution pipette is 15ml-20ml, and the azo dye contains one or more azo groups (-N=N-) in its molecular structure. These azo groups are unstable and prone to redox reactions. Sodium dithionite is used as a reducing agent to reduce the azo dye to the corresponding aromatic amine derivative, so that the obtained aromatic amine extract contains aromatic amine derivatives and some impurities, and then the aromatic amine extract is concentrated and dried to obtain the aromatic amine derivatives in the infiltration test solution; it can be understood that after the infiltration test solution is added with a primary alcohol solvent, the primary alcohol solvent reacts with isocyanate to generate a major carbamate compound, such as ethanol reacts with isocyanate to generate ethyl acetic acid isocyanate, thereby consuming isocyanate. Prevent isocyanate from reacting with aromatic amines generated by the reduction of azo dyes, thereby reducing the influence of isocyanate on the content of the obtained aromatic amine derivatives.

[0057] S107: pipette a fixed amount of the infiltration test solution, add di-n-butylamine to the infiltration test solution for extraction and derivatization to obtain a urea derivative solution, and dry the urea derivative solution to obtain a urea derivative mixture. In this embodiment, the amount of the infiltration test solution pipette is 15ml-20ml, and the amount of the second infiltration test solution is the same as that of the first infiltration test solution. The infiltration test solution contains isocyanate-type harmful substances, and the isocyanate group of isocyanate reacts with the amino group of di-n-butylamine to generate urea derivatives and water, so that the isocyanate extract also contains urea derivatives and some impurities. The isocyanate extract is dried to obtain the urea derivative in the infiltration test solution.

[0058] S109: The aromatic amine derivative mixture and the urea derivative mixture are fixed to volume with methanol to obtain a test solution. In this embodiment, methanol is a polar solution and has good solubility for urea derivatives and aromatic amine derivatives. The amount of the test solution after the fixed volume is the same as the amount of the first immersion test solution, so that the content of cyanate derivatives and aromatic amine derivatives in the test solution corresponds to the content of harmful substances in the transferred immersion test solution, so that the calculation of the test solution is convenient and the test result is accurate.

[0059] S111 performs instrumental analysis on the standard working solution of the azo dye and isocyanate harmful substances and the test solution. In this embodiment, the urea derivatives and aromatic amine derivatives of the test solution and the methanol mixture are analyzed by GC-MS, and then the standard working solution of the azo dye and isocyanate harmful substances and the test solution are detected and analyzed by the spike method. By comparing the test solution with the standard working solution of the azo dye and isocyanate harmful substances and performing spike detection, the content of these substances in the methanol mixture can be accurately detected, thereby evaluating the safety and compliance of the product.

[0060] The above-mentioned method for determining harmful substances of azo dyes and isocyanates in textiles comprises the following steps: removing impurities from the impregnated test solution and then performing reduction extraction to obtain an aromatic amine derivative mixture; extracting the impregnated test solution and then performing derivatization to obtain a urea derivative mixture; re-converting the aromatic amine derivative mixture and the urea derivative mixture to obtain a test solution; when the test solution is subjected to instrumental analysis, the contents of azo dyes and isocyanates reacted with the aromatic amine derivative and urea derivative mixture of the test solution are determined; in the process of obtaining the aromatic amine derivative mixture and the urea derivative mixture, other impurities are purified, and interference with the test results is reduced, thereby improving the accuracy of azo dyes and isocyanates measured by the test solution; and a variety of azo dyes and a variety of isocyanates are detected at the same time, thereby improving the detection efficiency and reducing the detection cost.

[0061] In one embodiment, when the standard working solution of azo dyes and isocyanate harmful substances and the test solution are subjected to instrumental analysis, the gas chromatography conditions are:

[0062] Chromatographic column: elastic capillary column, stationary phase is (50% phenyl)-methylpolysiloxane, specifications are [30m (length) x 0.25mm (inner diameter) x 0.25 um (film thickness)]; injection port temperature: 280℃; carrier gas: helium (purity>99.999%), constant flow rate: 1.0mLmin; injection volume: 1m, split injection, split ratio is 10:1; heating program: initial temperature 50℃, hold for 1min; increase to 280℃ at a rate of 5℃ / min, hold for 8min;

[0063] Mass spectrometry conditions: transmission line temperature: 280°C. Ionization mode: electron impact source (EI); ionization energy: 70eV; ion source temperature: 230°C; quadrupole temperature: 150°C; determination mode: selected ion monitoring mode (SIM) scanning; solvent delay 8min. In this embodiment, the liquid to be tested is separated into various compound components in the gas chromatography column, and the time and peak shape information of each compound is output through the detector. The mass spectrometry process decomposes complex substances into basic ions, and then separates, detects and identifies them, thereby obtaining accurate analysis results of the liquid to be tested.

[0064] In one embodiment, sodium dithionite is added to the azo test solution for reduction extraction, comprising the following steps:

[0065] Adding a sodium dithionite aqueous solution to the azo test solution for water bath reduction to obtain a reduced solution;

[0066] Putting the reducing solution into ice water to cool the reducing solution to 20° C.-25° C. to obtain a cooling solution;

[0067] The cooled solution is transferred into an extraction diatomaceous earth column, and tert-butyl methyl ether is added for extraction and elution to obtain an aromatic amine extract.

[0068] In this embodiment, an aqueous solution of sodium dithionite is added to the azo test solution for water bath reduction, and the reduced solution is placed in ice water so that the cooled solution is stable, which is conducive to the next step of extraction and elution of the cooled solution. The cooled solution is poured into an extraction diatomite column, and the extraction diatomite column adsorbs and enriches the target aromatic amine in the cooling solution, so that the aromatic amine is enriched in a smaller volume, thereby increasing the concentration of the target, and then the aromatic amine is eluted and collected by tert-butyl methyl ether. In gas chromatography-mass spectrometry analysis, increasing the concentration of aromatic amines can improve the sensitivity of detection, make the detection limit lower, and be able to detect the content of aromatic amines at lower concentrations.

[0069] Tert-butyl methyl ether has stable chemical properties, and the distribution coefficient of aromatic amines in tert-butyl methyl ether is large, which makes tert-butyl methyl ether have a better extraction effect on aromatic amines. The tert-butyl group in the tert-butyl methyl ether molecule has a large steric hindrance, and this steric hindrance effect can stabilize free radicals, thereby resisting oxidation reactions inside and outside the molecule. In addition, the methyl group in the tert-butyl methyl ether molecule also has a certain antioxidant effect, which can capture free radicals and weaken or eliminate the oxidation reaction with oxygen in the molecule. Therefore, compared with ether, tert-butyl methyl ether has better antioxidant stability, and the extraction effect of aromatic amines using tert-butyl methyl ether as an extractant is more stable.

[0070] Furthermore, in one embodiment, before pouring the cooling solution into the extraction diatomaceous earth column, the cooling solution is subjected to adsorption purification, including the following steps:

[0071] Pour the cooled solution into the adsorption diatomaceous earth column and let it stand for 15-20 minutes;

[0072] Add tert-butyl methyl ether and shake vigorously to obtain a purified cooling solution;

[0073] The purified cooled solution is transferred into an extraction diatomaceous earth column, tert-butyl methyl ether is added to wash the adsorption diatomaceous earth column, and the washing liquid for washing the adsorption diatomaceous earth column is transferred into the extraction diatomaceous earth column.

[0074] In this embodiment, various impurities, such as dust, grease, fiber fragments, etc., may be introduced into the textile during production and processing. Diatomaceous earth has a porous structure and a large specific surface area, which can effectively adsorb these impurities, thereby reducing their interference with subsequent detection. For some impurities with strong polarity, diatomaceous earth can also be adsorbed through the polar groups on the surface to improve the purity of the sample. Pure samples can obtain better chromatographic separation effects in gas chromatography analysis. The adsorption diatomaceous earth column filtration removes impurities and interferences, making the separation of azo dyes on the chromatographic column clearer and the peak shape sharper, which is conducive to accurate quantitative and qualitative analysis.

[0075] In one embodiment, the temperature for heating and soaking after adding the artificial sweat to the textile sample is 70±2°C, and the soaking time is 30±1min. The temperature for water bath removal of impurities by adding primary alcohol solvent to the soaking test solution is 70±2°C, and the water bath removal time is 30±1min. The temperature for water bath reduction is 70±2°C, and the water bath reduction time is 30±1min. In this embodiment, the soaking efficiency of artificial sweat and textile samples can be improved by heating and soaking, so that azo dyes and isocyanates can enter the soaking test solution faster; the heating of water bath removal can accelerate the efficiency of ethanol consumption of isocyanates, thereby reducing the influence of isocyanates on aromatic amines; the heating of sodium dithionite reduction extraction to the azo test solution accelerates the speed of azo test solution converting aromatic amines; at the same time, the temperature conditions are all set to 70±2°C and the time is all set to 30±1min, which reduces temperature changes, simplifies the operation steps, saves operation time, and thus accelerates the detection speed.

[0076] In one embodiment, after obtaining the cooling solution and before pouring the cooling solution into the extraction diatomaceous earth column, the method further comprises the following steps:

[0077] Add sodium hydroxide solution to the cooling solution and carry out mixing and oscillating treatment. In the present embodiment, the sodium hydroxide solution concentration is 10%, and after adding sodium hydroxide solution to the cooling solution, an alkaline system is formed after mixing and oscillating in a vortex mixing oscillator. Under alkaline conditions, there are a large amount of hydroxide ions in the solution. Because aromatic amines have alkalinity, they can coexist with hydroxide ions without significant reaction. Therefore, aromatic amines are usually stable in the form of free state in alkaline solution. By adding sodium hydroxide solution, the cooling solution is adjusted to alkalinity, which is conducive to sodium dithionite and azo dyes to react and generate aromatic amines, and the aromatic amines converted by the azo dyes in the cooling solution are more thorough through vigorous oscillation.

[0078] In one embodiment, drying the aromatic amine extract comprises the following steps:

[0079] The aromatic amine extract is transferred to a low vacuum rotary evaporator for concentration at a heating temperature of 35° C. to 45° C. to obtain a concentrated extract;

[0080] The concentrated extract is blown dry by an inert gas to obtain an aromatic amine derivative mixture.

[0081] In this embodiment, the cooled solution is eluted with tert-butyl methyl ether, so that the collected aromatic amine extract contains a large amount of tert-butyl methyl ether, so the aromatic amine extract needs to be concentrated and then the concentrated extract is dried. The boiling point of tert-butyl methyl ether is 55°C-57°C. The aromatic amine extract is concentrated under low vacuum conditions by a low vacuum rotary evaporator, so that the boiling point of the solvent tert-butyl methyl ether is reduced, thereby accelerating the evaporation rate of tert-butyl methyl ether. At the same time, a relatively low temperature can be maintained during the concentration process, avoiding the destruction of the substance of the aromatic amine extract by high temperature, and obtaining a concentrated extract in a stable state. Then, the inert gas of the nitrogen blower is purged to replace the saturated steam, thereby slowly drying the concentrated extract to obtain an aromatic amine derivative mixture.

[0082] In one embodiment, di-n-butylamine is added to the infiltration test solution for extraction and derivatization, comprising the following steps:

[0083] adding dichloromethane to the infiltration test solution and mixing to obtain an extraction mixture;

[0084] The extraction mixture is centrifuged at a centrifugal speed of more than 4000 r / min for 5-10 min, and after standing and stratification, an upper layer of extraction liquid and a lower layer of liquid are formed;

[0085] removing the upper layer of the extract;

[0086] A di-n-butylamine-dichloromethane solution is added to the upper extract, and after ultrasonic extraction and derivatization, a urea derivative solution is obtained.

[0087] In this embodiment, di-n-butylamine and dichloromethane are miscible to form a di-n-butylamine-dichloromethane solution; after dichloromethane is mixed with the infiltration test solution, dichloromethane extracts isocyanate and other impurities in the infiltration test solution, and the extraction mixture is centrifuged at a centrifugal speed of more than 4000r / min, so that the upper layer of extract and the lower layer of liquid are formed after stratification, and the stratification effect is better, and the upper layer of extract is a mixture of dichloromethane, azo dye and isocyanate; after the di-n-butylamine-dichloromethane solution is added to the upper layer of extract, di-n-butylamine does not react with the azo dye, and di-n-butylamine reacts with isocyanate to form urea derivatives, and the urea derivative liquid contains urea derivatives, di-n-butylamine, dichloromethane solution and other impurities.

[0088] It is understandable that urea derivatives have good solubility in dichloromethane. The physical and chemical properties of dichloromethane are stable, so that dichloromethane maintains high accuracy and stability during the extraction process. The boiling point of dichloromethane is 39.8°C, so that the dichloromethane in the urea derivative liquid can be volatilized at a lower temperature, which is convenient for drying the urea derivative liquid.

[0089] Furthermore, when the urea derivative liquid is dried, the urea derivative liquid is blown dry by nitrogen gas at 40° C. to 45° C. There is less dichloromethane in the urea derivative liquid, and the dichloromethane is blown dry by nitrogen gas, so that the urea derivative liquid is dried quickly.

[0090] In one of the embodiments, further, after adding the dichloromethane to the infiltration test solution to obtain the extraction mixture, before centrifuging the extraction mixture, 1 ml to 2 ml of sodium hydroxide solution is added to the extraction mixture, and the concentration of the sodium hydroxide solution is 10%. In this embodiment, the artificial sweat in the infiltration test solution is acidic, and the addition of sodium hydroxide solution neutralizes the acidity of the infiltration test solution. The alkaline environment is more conducive to the reaction of di-n-butylamine with isocyanate. The upper extract after separation by adding the hydrogen-oxygen extraction mixture is alkaline, so that the effect of di-n-butylamine reacting with isocyanate to generate urea derivatives is better, so that the result of the detection of urea derivatives is more accurate.

[0091] In one embodiment, before centrifuging the extraction mixture, after adding dichloromethane to the infiltration test solution, the following steps are also included:

[0092] The extraction mixture was vortexed at a speed of 2000 r / min for 10-15 min.

[0093] In this embodiment, the extraction mixture is vortex-oscillated by a vortex oscillator, and the vortex oscillator is oscillated at a high frequency of 2000 r / min for 10-15 minutes, so that the dichloromethane and the isocyanate in the extracted wetting test solution are fully in contact and interact with each other, thereby shortening the extraction time and ensuring the uniformity and stability of the extraction mixture before centrifugation, thereby improving the centrifugal effect.

[0094] In one embodiment, the process of making the aromatic amine derivative mixture and the urea derivative mixture constant in volume with methanol comprises the following steps:

[0095] Transferring the aromatic amine derivative mixture to a container with methanol to obtain a primary fixed volume solution;

[0096] The urea derivative mixture is washed with methanol into a primary volumetric solution in the same container, and the volume is secondarily made up with methanol to obtain a solution to be tested.

[0097] In this embodiment, the aromatic amine derivative mixture and the urea derivative mixture are washed into the same container by methanol, which can reduce the residues of the aromatic amine derivative mixture and the urea derivative mixture during the transfer process, thereby improving the accuracy of the detection results. The concentrations of the aromatic amine derivatives and the urea derivatives in the test liquid can be accurately controlled through constant volume and secondary constant volume. Testing the test liquid can ensure the accuracy of the analysis and detection results, and also simplify the detection steps of the subsequent analysis without the need for cumbersome separation and purification operations.

[0098] Furthermore, in one embodiment, after the second constant volume with methanol and before the instrumental analysis of the test liquid, the following steps are also included:

[0099] The test liquid was vortexed for 60 seconds;

[0100] The liquid to be tested is filtered through a microporous membrane, and the thickness of the microporous membrane is 0.2 μm-0.22 μm.

[0101] In this embodiment, the components in the test liquid are fully mixed in the solution by vortex oscillation for 60 seconds to ensure that the components are evenly distributed. The uniform solution ensures the accuracy and reliability of the instrument analysis results and avoids repeated analysis or error correction due to uneven solutions. Moreover, vortex oscillation can accelerate the dissolution process of slightly soluble or insoluble substances that may exist in the test liquid in the solvent. This helps to reduce the analysis error caused by incomplete dissolution; the microporous filter membrane can effectively remove tiny particles, suspended matter and other impurities in the test liquid, avoiding the interference of impurities with the instrument analysis. At the same time, the pure test liquid can reduce the pollution and wear inside the instrument, thereby extending the service life of the instrument.

[0102] Further, in one embodiment, preparing artificial sweat comprises the following steps:

[0103] L-histidine hydrochloride monohydrate (C6H 10 CLN3O2·H2O), sodium chloride (NaCl) and disodium hydrogen phosphate dihydrate (Na2HPO4·2H2O) are added to water and dissolved to obtain artificial sweat.

[0104] In this embodiment, the preparation of artificial sweat can simulate the chemical composition and properties of natural human sweat and simulate the migration of harmful substances in textiles in the actual process, thereby making the determination results of azo dyes and isocyanate harmful substances in textiles more accurate.

[0105] Furthermore, the pH value of the artificial sweat is adjusted to 4.5-5.5, and sodium hydroxide solution is added dropwise to the container, while the pH value of the artificial sweat is monitored with an acidometer. Continue to drop until the pH value of the artificial sweat reaches the acidic range of 4.5-5.5. By accurately controlling the parameters such as the composition and pH value of the artificial sweat, the accuracy and reliability of the experimental results can be ensured. The artificial sweat is acidic, so that the configured infiltration test solution is acidic. When the infiltration test solution is added with a primary alcohol solvent for water bath impurity removal, under acid catalysis, the hydroxyl group (OH) in the primary alcohol solvent is first protonated to form an ethoxy ion (CH3CH2O+). The ethoxy ion attacks the carbon atom (the carbon atom directly connected to the nitrogen atom) in the isocyanate as a nucleophilic reagent to form a new carbon-oxygen bond, thereby generating an ester compound. In this process, the acid acts as a catalyst to promote the protonation of ethanol and accelerate the nucleophilic addition reaction, so that the infiltration test solution has a better effect of removing isocyanates.

[0106] In one embodiment, preparing a standard working solution of azo dye substances and isocyanate substances comprises the following steps:

[0107] The preparation of standard working solutions of azo dyes and isocyanates comprises the following steps:

[0108] Dissolve the harmful substances of azo dyes and isocyanates in methanol to obtain primary standard stock solutions of harmful substances of azo dyes and isocyanates;

[0109] The primary standard stock solutions of harmful substances of nitrogen dyes and isocyanates are respectively prepared with methanol to obtain standard working solutions of azo dyes and isocyanates of different concentrations. In the present embodiment, methanol is a polar solvent, which has good solubility for azo dyes and isocyanates. By preparing high-purity standard working solutions of nitrogen dyes and isocyanates, the standard working solutions have a certain gradient and range in concentration, which can meet different analytical detection requirements, while ensuring the accuracy and reliability of the analytical results, and are convenient for spiked detection with the test solution.

[0110] In one embodiment, the harmful substances of isocyanate include 4,4-methylenebis(phenyl isocyanate), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), tetramethyl-m-hydroxyethyl diisocyanate (TMXDI), cyclohexyl isocyanate, isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI), polymeric diphenylmethane diisocyanate (pMDI), toluene diisocyanate, 2,6-diisocyanate toluene, m-xylene diisocyanate, 2,6-diisopropylphenyl-isocyanate, isopropylphenyl isocyanate, 3-carboxyphenyl isocyanate, methyl isocyanate, and n-heptyl isocyanate; the azo dye substances include aniline, o-toluidine, 2.6- At least one of dimethylaniline, 2.4-dimethylaniline, o-anisidine, naphthalene-d8, p-chloroaniline, p-phenylenediamine, 3-amino-p-toluene, 2.4.5-trimethylaniline, 4-chloro-2-methylaniline, 2.4-diaminotoluene, 2.4-diaminoanisole, 2.4.5-trichloroaniline, 2-naphthylamine, 2-amino-4-nitrotoluene, anthracene-D10, 4-aminoazobenzene, 4.4-diaminodiphenyl ether, benzidine, 4.4-diaminodiphenylmethane, o-aminoazotoluene, 4.4-diamino-3.3-dimethylbiphenylmethane, o-toluidine, 4.4-diaminodiphenyl sulfide, 3.3-dichlorobenzidine, 4.4-diamino-3.3-dichlorodiphenylmethane, dianisidine, and o-toluidine. In this embodiment, the textile contains a variety of isocyanates and azo dyes that are harmful to the human body and the environment. By simultaneously detecting the multiple isocyanates and azo dyes contained in the textile, the detection efficiency is improved and the cost is reduced.

[0111] Compared with the prior art, the present invention has at least the following advantages:

[0112] The above-mentioned method for determining harmful substances of azo dyes and isocyanates in textiles comprises the following steps: removing impurities from the impregnated test solution and then performing reduction extraction to obtain an aromatic amine derivative mixture; extracting the impregnated test solution and then performing derivatization to obtain a urea derivative mixture; re-converting the aromatic amine derivative mixture and the urea derivative mixture to obtain a test solution; when the test solution is subjected to instrumental analysis, the contents of azo dyes and isocyanates reacted with the aromatic amine derivative and urea derivative mixture of the test solution are determined; in the process of obtaining the aromatic amine derivative mixture and the urea derivative mixture, other impurities are purified, and interference with the test results is reduced, thereby improving the accuracy of azo dyes and isocyanates measured by the test solution; and a variety of azo dyes and a variety of isocyanates are detected at the same time, thereby improving the detection efficiency and reducing the detection cost.

[0113] Some specific examples are listed below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0114] Example 1

[0115] Prepare standard working solution, 4.4-methylenebis(phenyl isocyanate), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), tetramethyl-m-hydroxyethyl diisocyanate (TMXDI), cyclohexyl isocyanate, isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI), polymeric diphenylmethane diisocyanate (pMDI), toluene diisocyanate, 2,6-diisocyanatotoluene, m-xylene diisocyanate, 2,6-diisopropylphenyl-isocyanate, isopropylphenyl isocyanate, 3-carboxyphenyl isocyanate, methyl isocyanate, n-heptyl isocyanate, aniline, o-toluidine, 2.6-dimethylaniline, 2.4-dimethylaniline, o-methoxyaniline, naphthalene-d8, p-chloroaniline, p-phenylenediamine, 3-amino-p-toluene Methyl ether, 2.4.5-trimethylaniline, 4-chloro-2-methylaniline, 2.4-diaminotoluene, 2.4-diaminoanisole, 2.4.5-trichloroaniline, 2-naphthylamine, 2-amino-4-nitrotoluene, anthracene-D10, 4-aminoazobenzene, 4.4-diaminodiphenyl ether, benzidine, 4.4-diaminodiphenylmethane, o-aminoazotoluene, 4.4-diamino-3.3-dimethylbiphenylmethane, o-tolidine, 4.4-diaminodiphenyl sulfide, 3.3-dichlorobenzidine, 4.4-diamino-3.3-dichlorodiphenylmethane, dianisidine and o-toluidine are dissolved in methanol to make up to volume to obtain primary standard working solutions of different substances, and the standard working solutions of the above different substances are respectively prepared with methanol to obtain standard working solutions with different concentration gradients for standby use;

[0116] Weigh 0.5 g of L-histidine hydrochloride monohydrate (C6H10CLN3O2·H2O), 5 g of sodium chloride (NaCl), and 2.5 g of disodium hydrogen phosphate dihydrate (Na2HPO4·2H2O). Add 1000 mL of distilled water into a 2 L beaker and stir continuously until the added reagents are completely dissolved to obtain artificial sweat.

[0117] Cut a certain amount of clothing textile sample into small pieces of about 5mm*5mm, weigh 2g of clothing textile sample, add 60ml of artificial sweat to the textile, place it in a constant temperature water bath at 70±2℃ for 30±1min, and obtain the infiltration test solution.

[0118] Transfer 15 ml of the infiltration test solution to a 50 ml threaded test tube, add 3 ml of ethanol, tighten the cap immediately and shake vigorously, then place in a constant temperature water bath at 70 ± 2 ° C for 30 ± 1 min to obtain an azo test solution, then quickly add 3 ml of freshly prepared sodium dithionite aqueous solution to the azo test solution in the threaded test tube, immediately tighten the cap and shake vigorously, then place in a constant temperature water bath at 70 ± 2 ° C for 30 ± 1 min to obtain a reduction solution, and after the insulation, quickly put the test tube of the reduction solution into an ice water bath, cool to room temperature within 3 min to obtain a cooling solution, add 0.2 ml of 10% sodium hydroxide solution to a 50 ml threaded test tube for mixed oscillation, transfer the obtained cooling solution to a silica gel column for 15 min of static adsorption, add 10 ml of tert-butyl methyl ether to the reactor and shake vigorously. After the 15 min adsorption is completed, immediately pour the tert-butyl methyl ether and the obtained cooling solution into the diatomaceous earth column. Then add 10 mL of tert-butyl methyl ether to rinse the reactor, transfer the washing liquid to the diatomaceous earth column, and finally use a 100 mL measuring cylinder to take 100 mL of tert-butyl methyl ether and pour it into the diatomaceous earth column, and collect it in a 250 mL chicken heart bottle to obtain the aromatic amine extract. Under the condition of 35-45 ° C, use a low vacuum rotary evaporator to concentrate the aromatic amine extract to nearly 1 mL to obtain a concentrated extract, and slowly blow the concentrated extract to nearly dryness with a low flow rate inert gas to obtain an aromatic amine derivative mixture, and use 3 mL of methanol to elute the aromatic amine derivative mixture in the chicken heart bottle in small amounts and multiple times and transfer it to a 10 mL volumetric flask.

[0119] 15 mL of the sample solution of the soaking test solution was transferred to a 20 mL test tube, 5 mL of dichloromethane was added, the tube was sealed, and the mixture was vortexed at 2000 r / min for 10 min, centrifuged at 4000 r / min for 5-10 min, and then allowed to stand for stratification. 5 mL of the upper extract was accurately transferred to a stoppered colorimetric tube, 4 mL of 0.5 g / L di-n-butylamine-dichloromethane solution was added, and the urea derivative solution was obtained by ultrasonic extraction and derivatization for 60 min. The urea derivative solution was blown to near dryness by nitrogen at 40 ° C to obtain a urea derivative mixture. The urea derivative mixture in the stoppered colorimetric tube was eluted with about 3 mL of methanol in small amounts and multiple times, and transferred to a 10 mL volumetric flask containing an aromatic amine derivative mixture. Finally, the volume was adjusted to the mark with methanol to obtain a clothing textile test solution. After the clothing textile test solution was vortexed for 60 s, the clothing textile test solution was filtered through a 0.22 μm microporous filter membrane, and the clothing textile test solution was analyzed and determined by instrumental analysis.

[0120] Example 2

[0121] Cut a certain amount of decorative fabric textile sample, cut it into small pieces of about 5mm*5mm and mix them, weigh 2g of decorative fabric textile sample. Add 60ml of artificial sweat to the decorative fabric textile sample, place it in a constant temperature water bath at 70±2℃ and keep it warm for 30±1min to obtain the infiltration test solution.

[0122] Transfer 15 ml of the infiltration test solution to a 50 mL threaded test tube, add 3 mL of ethanol, tighten the cap immediately and shake vigorously, then place it in a constant temperature water bath at 70 ± 2 ° C for 30 ± 1 min to obtain an azo test solution, then quickly add 3 mL of freshly prepared sodium dithionite aqueous solution to the azo test solution in the threaded test tube, immediately tighten the cap and shake vigorously, then place it in a constant temperature water bath at 70 ± 2 ° C for 30 ± 1 min to obtain a reduction solution, and after the insulation is completed, quickly put the test tube of the reduction solution into an ice water bath, cool to room temperature within 3 min to obtain a cooling solution, add 0.2 mL of 10% sodium hydroxide solution to a 50 mL threaded test tube for mixed oscillation, transfer all the cooling solution to a silica gel column and let it stand for adsorption for 15 min, add 10 mL of tert-butyl methyl ether to the reactor and shake vigorously. After the 15 min adsorption is completed, immediately pour the tert-butyl methyl ether and the obtained cooling solution into the diatomaceous earth column. Then add 10 mL of tert-butyl methyl ether to rinse the reactor, transfer the washing liquid to the diatomaceous earth column, and finally use a 100 mL measuring cylinder to take 100 mL of tert-butyl methyl ether and pour it into the diatomaceous earth column, and collect it in a 250 mL chicken heart bottle to obtain the aromatic amine extract. Under the condition of 35-45 ° C, use a low vacuum rotary evaporator to concentrate the aromatic amine extract to nearly 1 mL to obtain a concentrated extract, and slowly blow the concentrated extract to nearly dryness with a low flow rate inert gas to obtain an aromatic amine derivative mixture, and use 3 mL of methanol to elute the aromatic amine derivative mixture in the chicken heart bottle in small amounts and multiple times and transfer it to a 10 mL volumetric flask.

[0123] Pipette 15 mL of the sample solution infiltrated with the test solution into a 20 mL test tube, add 5 mL of dichloromethane, seal the tube with a lid, vortex at 2000 r / min for 10 min, centrifuge at 4000 r / min for 5-10 min, and then let stand to separate the layers. Accurately transfer 5 mL of the upper extract into a stoppered colorimetric tube, add 4 mL of 0.5 g / L di-n-butylamine-dichloromethane solution, perform ultrasonic extraction and derivatization for 60 min to obtain a urea derivative solution, blow the urea derivative solution to near dryness with nitrogen at 40 °C to obtain a urea derivative mixture, elute the urea derivative mixture in the stoppered colorimetric tube with about 3 mL of methanol in small amounts for multiple times, and transfer it to a 10 mL volumetric flask containing an aromatic amine derivative mixture, and finally dilute to the scale with methanol to obtain a clothing textile test solution. After the decorative fabric textile test solution is vortexed for 60 s, the decorative fabric textile test solution is filtered through a 0.22 μm microporous filter membrane and analyzed and determined by instrumentation to obtain the decorative fabric textile test solution.

[0124] Example 3

[0125] Cut a certain amount of leather textile sample, cut it into small pieces of about 5mm*5mm and mix them, weigh 2g of leather textile sample. Add 60ml of artificial sweat to the leather textile sample, place it in a constant temperature water bath at 70±2℃ and keep it warm for 30±1min to obtain the infiltration test solution.

[0126] Transfer 15 ml of the infiltration test solution to a 50 mL threaded test tube, add 3 mL of ethanol, tighten the cap immediately and shake vigorously, then place it in a constant temperature water bath at 70 ± 2 ° C for 30 ± 1 min to obtain an azo test solution, then quickly add 3 mL of freshly prepared sodium dithionite aqueous solution to the azo test solution in the threaded test tube, immediately tighten the cap and shake vigorously, then place it in a constant temperature water bath at 70 ± 2 ° C for 30 ± 1 min to obtain a reduction solution, and after the insulation is completed, quickly put the test tube of the reduction solution into an ice water bath, cool to room temperature within 3 min to obtain a cooling solution, add 0.2 mL of 10% sodium hydroxide solution to a 50 mL threaded test tube for mixed oscillation, transfer all the cooling solution to a silica gel column and let it stand for adsorption for 15 min, add 10 mL of tert-butyl methyl ether to the reactor and shake vigorously. After the 15 min adsorption is completed, immediately pour the tert-butyl methyl ether and the obtained cooling solution into the diatomaceous earth column. Then add 10 mL of tert-butyl methyl ether to rinse the reactor, transfer the washing liquid to the diatomaceous earth column, and finally use a 100 mL measuring cylinder to take 100 mL of tert-butyl methyl ether and pour it into the diatomaceous earth column, and collect it in a 250 mL chicken heart bottle to obtain the aromatic amine extract. Under the condition of 35-45 ° C, use a low vacuum rotary evaporator to concentrate the aromatic amine extract to nearly 1 mL to obtain a concentrated extract, and slowly blow the concentrated extract to nearly dryness with a low flow rate inert gas to obtain an aromatic amine derivative mixture, and use 3 mL of methanol to elute the aromatic amine derivative mixture in the chicken heart bottle in small amounts and multiple times and transfer it to a 10 mL volumetric flask.

[0127] Pipette 15 mL of the sample solution infiltrated with the test solution into a 20 mL test tube, add 5 mL of dichloromethane, seal the tube with a lid, vortex at 2000 r / min for 10 min, centrifuge at 4000 r / min for 5-10 min, and then let stand to separate the layers. Accurately transfer 5 mL of the upper extract into a stoppered colorimetric tube, add 4 mL of 0.5 g / L di-n-butylamine-dichloromethane solution, perform ultrasonic extraction and derivatization for 60 min to obtain a urea derivative solution, blow the urea derivative solution to near dryness with nitrogen at 40 °C to obtain a urea derivative mixture, elute the urea derivative mixture in the stoppered colorimetric tube with about 3 mL of methanol in small amounts for multiple times, and transfer it to a 10 mL volumetric flask containing an aromatic amine derivative mixture, and finally dilute to the scale with methanol to obtain a leather textile test solution. After the leather textile test solution is vortexed for 60 s, the leather textile test solution is filtered through a 0.22 μm microporous filter membrane, and the standard working solution of each substance is added for spiked test, and the leather textile test solution is determined by instrumental analysis.

[0128] Comparative Example 1

[0129] A certain amount of clothing textile samples were cut and tested according to the standard of GB / T 17592-2011 Determination of banned azo dyes in textiles, and the clothing textile samples of comparative example 1 were analyzed and measured by instrument.

[0130] Comparative Example 2

[0131] A certain amount of clothing textile samples were cut and tested according to the standard of GB / T 17592-2011 Determination of banned azo dyes in textiles, and standard working solutions of various substances were added for spiked testing. The clothing textile samples of comparative example 2 were analyzed and determined by instruments.

[0132]

[0133]

[0134] Table 2 Determination results of isocyanate of samples of Examples 1-3

[0135]

[0136] The above ND means less than the detection limit, and na means not detected. Comparative Examples 1 and 2 were detected by the national standard method, so isocyanate was not determined in Comparative Examples 1 and 2.

[0137] As can be seen from Table 1 and Table 2, Comparative Example 1, Comparative Example 2 and Examples 1-3 can all detect a variety of azo dyes in textiles. Among them, Example 1 and Comparative Example 1 detect clothing textile samples, and Example 2 detects decorative fabric textile samples. Compared with the detection of Examples 1-3, the samples of Examples 1 and 2 do not contain isocyanate harmful substances or the content is less than the detection limit, the leather textile sample of Example 3 contains polyurethane, and Example 3 detects a variety of isocyanates. The determination method of azo dyes and isocyanate harmful substances in textiles can simultaneously detect the contents of a variety of azo dyes and a variety of isocyanates in Examples 1-3;

[0138] According to Figures 3 to 7 The test sample results of an embodiment shown in the figure can obtain clear chromatograms of various azo dyes and various isocyanates in the test sample after being tested by the determination method of harmful substances of azo dyes and isocyanates in textiles, so as to accurately determine the contents of various azo dyes and various isocyanates.

[0139] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A method for determining harmful substances such as azo dyes and isocyanates in textiles, characterized in that: The following steps are involved: Prepare standard working solutions of azo dyes and isocyanate hazardous substances; preparing artificial sweat and a textile sample, adding the artificial sweat to the textile sample and then heating and infiltrating the textile sample to obtain an infiltration test solution; Pipetting a certain amount of the infiltration test solution, adding a primary alcohol solvent to the infiltration test solution for water bath removal to obtain an azo test solution, adding sodium dithionite to the azo test solution for reduction extraction to obtain an aromatic amine extract solution, and drying the aromatic amine extract solution to obtain an aromatic amine derivative mixture; Pipetting a certain amount of the infiltration test solution, adding di-n-butylamine to the infiltration test solution for extraction and derivatization to obtain a urea derivative solution, and drying the urea derivative solution to obtain a urea derivative mixture; The aromatic amine derivative mixture and the urea derivative mixture are diluted to volume with methanol to obtain a test solution; Instrumental analysis is performed on the standard working solutions of the azo dyes and isocyanate harmful substances and the solution to be tested.

2. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 1, characterized in that: The azo test solution is added with sodium dithionite for reduction extraction, comprising the following steps: Adding a sodium dithionite aqueous solution to the azo test solution for water bath reduction to obtain a reduced solution; Putting the reducing solution into ice water to cool the reducing solution to 20° C.-25° C. to obtain a cooling solution; The cooled solution is transferred into an extraction diatomaceous earth column, and tert-butyl methyl ether is added for extraction and elution to obtain an aromatic amine extract.

3. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 2, characterized in that: The temperature for heating and infiltrating after adding the artificial sweat to the textile sample is 70±2°C, and the infiltration time is 30±1min. The temperature for water bath removal of impurities by adding primary alcohol solvent to the infiltration test solution is 70±2°C, and the water bath removal time is 30±1min. The temperature for water bath reduction is 70±2°C, and the water bath reduction time is 30±1min.

4. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 2, characterized in that: After obtaining the cooling solution, before pouring the cooling solution into the extraction diatomaceous earth column, the method further comprises the following steps: A sodium hydroxide solution is added to the cooled solution to carry out mixing and shaking treatment.

5. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 1, characterized in that: Drying the aromatic amine extract comprises the following steps: The aromatic amine extract is transferred to a low vacuum rotary evaporator for concentration at a heating temperature of 35° C. to 45° C. to obtain a concentrated extract; The concentrated extract is blown dry by an inert gas to obtain an aromatic amine derivative mixture.

6. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 1, characterized in that: Adding di-n-butylamine to the infiltration test solution for extraction and derivatization comprises the following steps: adding dichloromethane to the infiltration test solution and mixing to obtain an extraction mixture; The extraction mixture is centrifuged at a centrifugal speed of more than 4000 r / min for 5-10 min, and after standing and stratification, an upper layer of extraction liquid and a lower layer of liquid are formed; removing the upper layer of the extract; A di-n-butylamine-dichloromethane solution is added to the upper extract, and after ultrasonic extraction and derivatization, a urea derivative solution is obtained.

7. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 6, characterized in that: Before centrifuging the extraction mixture, after adding dichloromethane to the infiltration test solution, the method further comprises the following steps: The extraction mixture was vortexed at a speed of 2000 r / min for 10-15 min.

8. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 1, characterized in that: The aromatic amine derivative mixture and the urea derivative mixture are constant volume with methanol, comprising the following steps: Transferring the aromatic amine derivative mixture to a container with methanol to obtain a primary fixed volume solution; The urea derivative mixture is washed with methanol into a primary volumetric solution in the same container, and the volume is secondarily made up with methanol to obtain a solution to be tested.

9. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 1, characterized in that: The preparation of standard working solutions of azo dyes and isocyanates comprises the following steps: Dissolve the harmful substances of azo dyes and isocyanates in methanol to obtain primary standard stock solutions of harmful substances of azo dyes and isocyanates; The primary standard stock solutions of harmful substances such as azo dyes and isocyanates are respectively prepared with methanol to obtain standard working solutions of azo dyes and isocyanates of different concentrations.

10. The method for determining harmful substances of azo dyes and isocyanates in textiles according to claim 9, characterized in that: The harmful substances of isocyanate include 4,4-methylenebis(phenyl isocyanate), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), tetramethyl-m-hydroxyethyl diisocyanate (TMXDI), cyclohexyl isocyanate, isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI), polymeric diphenylmethane diisocyanate (pMDI), toluene diisocyanate, 2,6-diisocyanate toluene, m-xylene diisocyanate, 2,6-diisopropylphenyl-isocyanate, isopropylphenyl isocyanate, 3-carboxyphenyl isocyanate, methyl isocyanate, and n-heptyl isocyanate; the harmful substances of azo dyes include aniline, o-toluidine, 2,6-dimethylaniline , 2.4-dimethylaniline, o-methoxyaniline, naphthalene-d8, p-chloroaniline, p-phenylenediamine, 3-amino-p-toluene, 2.4.5-trimethylaniline, 4-chloro-2-methylaniline, 2.4-diaminotoluene, 2.4-diaminoanisole, 2.4.5-trichloroaniline, 2-naphthylamine, 2-amino-4-nitrotoluene, anthracene-D10, 4-aminoazobenzene, 4.4-diaminodiphenyl ether, benzidine, 4.4-diaminodiphenylmethane, o-aminoazotoluene, 4.4-diamino-3.3-dimethylbiphenylmethane, o-toluidine, 4.4-diaminodiphenyl sulfide, 3.3-dichlorobenzidine, 4.4-diamino-3.3-dichlorodiphenylmethane, dianisidine, and o-toluidine.

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